Field Ion Microscopy of Radiation Effects in Metallic Materials

Radiation effects in metallic materials were investigated using the field ion microscopy technique. Modes of radiation exposure for development of amorphized states in subsurface regions of platinum are determined. It is found that the phenomenon of metal amorphization in the subsurface regions occurs up to a sample depth of 12 nm under an increase in the fluence to 1018 ions/cm2 and the above irradiation energies. The method of field ion microscopy was used to determine the threshold of nanopore formation in ion-implanted platinum. Experimental results on atomic-spatial investigation of radiative defect formation in surface layers of materials, initiated by neutron bombardment (of Pt, E > 0.1 MeV) and ion implantation (in Cu3Au: E = 40 keV, F = 1016 ion/m2, j = 10−3 A/cm2), are considered. Mechanisms of the radiation-induced development of nanostructures in subsurface metal regions have been analyzed based on field ion microscopy data. It is concluded that the modification of near-surface metal regions on a nanometer scale as a result of the interaction with Ar+ ion beams proceeds by several mechanisms

The innovative aspects of the fishing fleet development in the Russian exclave region

Our country has set a course for the economy modernisation on the basis of innovative development. In the post-war period until 1991, the exclave of Russia — the Kaliningrad region — showed high rates of socioeconomic development due to the establishment of a large- scale sea fishing industry. Such success rested on research and innovative activity. This article analyses the successful innovative development of the fishing fleet in the historical perspective: new vessels, the development of new equipment, introduction of innovative forms of fishing organisation. The authors offer data on the efficiency of such innovative initiatives. This historical experience is of great importance given the revival of industrial fishing in the Kaliningrad region

Spin dynamics of electrons in the first excited subband of a high-mobility low-density 2D electron system

We report on time-resolved Kerr rotation measurements of spin coherence of electrons in the first excited subband of a high-mobility low-density two-dimensional electron system in a GaAs/Al0.35Ga0.65As heterostructure. While the transverse spin lifetime (T2*) of electrons decreases monotonically with increasing magnetic field, it has a non-monotonic dependence on the temperature, with a peak value of 596 ps at 36 K, indicating the effect of inter-subband electron-electron scattering on the electron spin relaxation. The spin lifetime may be long enough for potential device application with electrons in excited subbands

Spatial statistics of passive scalar in two-dimensional shear flow with fluctuations

We examine statistical properties of the passive scalar field advected by the flow consisting of the regular shear flow and of irregular flow fluctuations. We consider the particular case of two-dimensional flow where the shear flow is dominating and the random flow is smooth. We examine both the decaying case and the case of the permanent supply of the passive scalar fluctuations. In both cases the passive scalar possesses strong intermittence, that can be characterized via the single-point moments and correlation functions, calculated in our work. We reveal features of the correlation functions related to the strong anisotropy of the flow. Our qualitative results are universal. Some quantitative results are obtained in the framework of the model where the flow fluctuations are short correlated in time.Comment: 14 pages, 2 figure

Current Trends of Membrane Technology Development

Мембранные технологии в настоящее время являются одними из самых востребованных. Об этом говорят их разнообразие и широкий спектр использования мембран в самых актуальных сферах жизнедеятельности человека, таких как опреснение и очистка воды, энергетика, медицина, химическая и нефтегазовая промышленность и др., что, в свою очередь, порождает интерес к изучению свойств мембран и разработке мембран нового поколения, а также дает импульс в расширении исследований и привлечении нанотехнологий в мембранную науку и практику. В данной статье описываются основные виды и принципы мембранного разделения, проводится обзор состояния мембранной индустрии, показаны актуальные научные достижения в производстве мембран, а также перспективы их дальнейшего развитияMembrane technologies are currently one of the most popular. This is indicated by their diversity and wide range of use of the membranes in the most relevant spheres of human activity, such as desalination and water treatment, energy, medicine, chemical and petroleum industry etc. It in turn generates interest in studying of membrane properties and the development of new generation membranes and also gives impetus to the expansion of research and the involvement of nanotechnology in membrane science and practice. This article describes the main types and principles of membrane separation, reviewed the status of membrane industry, the scientific advances in the production of membranes, provides an overview of the state of the membrane industry, shows relevant scientific advances in the production of membranes, as well as the prospects of their developmen

Eurasian-Scale Experimental Satellite-based Quantum Key Distribution with Detector Efficiency Mismatch Analysis

The Micius satellite is the pioneering initiative to demonstrate quantum teleportation, entanglement distribution, quantum key distribution (QKD), and quantum-secured communications experiments at the global scale. In this work, we report on the results of the 600-mm-aperture ground station design which has enabled the establishment of a quantum-secured link between the Zvenigorod and Nanshan ground stations using the Micius satellite. As a result of a quantum communications session, an overall sifted key of 2.5 Mbits and a total final key length of 310 kbits have been obtained. We present an extension of the security analysis of the realization of satellite-based QKD decoy-state protocol by taking into account the effect of the detection-efficiency mismatch for four detectors. We also simulate the QKD protocol for the satellite passage and by that validate our semi-empirical model for a realistic receiver, which is in good agreement with the experimental data. Our results pave the way to the considerations of realistic imperfection of the QKD systems, which are important in the context of their practical security.Comment: 8+2 pages, 5+2 figure

Ultrasonic attenuation measurements at very high SNR: correlation, information theory and performance

This paper describes a system for ultrasonic wave attenuation measurements which is based on pseudo-random binary codes as transmission signals combined with on-the-fly correlation for received signal detection. The apparatus can receive signals in the nanovolt range against a noise background in the order of hundreds of microvolts and an analogue to digital convertor (ADC) bit-step also in the order of hundreds of microvolts. Very high signal to noise ratios (SNRs) are achieved without recourse to coherent averaging with its associated requirement for high sampling times. The system works by a process of dithering – in which very low amplitude received signals enter the dynamic range of the ADC by 'riding' on electronic noise at the system input. The amplitude of this 'useful noise' has to be chosen with care for an optimised design. The process of optimisation is explained on the basis of classical information theory and is achieved through a simple noise model. The performance of the system is examined for different transmitted code lengths and gain settings in the receiver chain. Experimental results are shown to verify the expected operation when the system is applied to a very highly attenuating material – an aerated slurry

Use of an Energy-Efficient Vertical Tine Ripper to Improve Soil Condition Characteristics

В целях совершенствования технологии возделывания зерновых культур проведена оценка влияния традиционной минимальной обработки почвы и прямого посева на агрофизическое состояние почвы и продуктивность культур в севообороте. Отмечено, что минимализация обработки почвы и прямой посев культур в севообороте чистый пар – яровая пшеница – озимая рожь + овес – яровая пшеница на черноземе в Красноярской лесостепи способствуют сохранению доступной влаги весной и повышению содержания в почве подвижного фосфора и обменного калия к середине вегетации растений. При этом почва в слое 0–10 см становится плотной, а в горизонте 20–40 см остается рыхловато-плотноватой. При традиционной технологии обработки почвы урожайность яровой пшеницы Красноярская 12 по пару составила 3,2–3,4 т/га, при обработке дисковым орудием БДН – 2,9–3,2 т/га, при прямом посеве стерневой сеялкой – 2,6–2,9 т/га. Осенью в год посева получен урожай зеленой массы смеси овса и озимой ржи. Стерня, оставшаяся после скашивания зеленой массы, способствует накоплению снега и улучшает перезимовку озимой ржи, на следующий год формирующей урожай зерна в 1,5–2,1 т/га. Применение ресурсосберегающих технологий обработки почвы существенно снижает производственные затраты. При минимальной технологии трудозатраты сокращаются на 35,5 %, ГСМ – на 40,3 %, при использовании технологии прямого посева трудозатраты сократились на 49,1 %, ГСМ – на 64,2 % по сравнению с традиционной технологией, основанной на зяблевой вспашке. Повышению эффективности минеральных и органических удобрений при посеве культур по пару и по стерне будет способствовать обработка поверхности роторным вертикально-штыревым глубокорыхлителем после их внесенияIn order to improve the technology of cultivating grain crops, an assessment was made of the impact of traditional, minimal tillage and direct sowing on the agrophysical state of the soil and the productivity of crops in crop rotation. It is noted that the minimization of tillage and direct sowing of crops in the crop rotation pure fallow – spring wheat – winter rye + oats – spring wheat on chernozem in the Krasnoyarsk forest- steppe, contribute to the preservation of available moisture in spring and increase the content of mobile phosphorus and exchangeable potassium in the soil by the middle of the plant growing season. At the same time, the soil in the 0–10 cm layer becomes dense, and in the 20–40 cm layer it remains loose – dense. With the traditional technology of tillage, the yield of spring wheat Krasnoyarskaya 12 for a fallow was 3.2–3.4 t/ha; 2.9 t/ha. In autumn, in the year of sowing, a green mass of a mixture of oats and winter rye was harvested. The stubble left after mowing the green mass contributes to the accumulation of snow and improves the overwintering of winter rye, which forms a grain yield of 1.5–2.1 t/ha the next year. The use of resource-saving tillage technologies significantly reduces production costs. With the minimum technology, labor costs are reduced by 35.5 %, fuel and lubricants by 40.3 %, when using direct sowing technology, labor costs are reduced by 49.1 %, fuel and lubricants by 64.2 % compared to traditional technology based on autumn plowing. An increase in the efficiency of mineral and organic fertilizers when sowing crops in fallow and stubble will be facilitated by surface treatment with a rotary vertically pinned subsoiler after their applicatio

Prospects for seasonal forecasting of iceberg distributions in the North Atlantic

An efficient approach to ocean–iceberg modelling provides a means for assessing prospects for seasonal forecasting of iceberg distributions in the northwest Atlantic, where icebergs present a hazard to mariners each spring. The stand-alone surface (SAS) module that is part of the Nucleus for European Modelling of the Ocean (NEMO) is coupled with the NEMO iceberg module (ICB) in a “SAS-ICB” configuration with horizontal resolution of 0.25°. Iceberg conditions are investigated for three recent years, 2013–2015, characterized by widely varying iceberg distributions. The relative simplicity of SAS-ICB facilitates efficient investigation of sensitivity to iceberg fluxes and prevailing environmental conditions. SAS-ICB is provided with daily surface ocean analysis fields from the global Forecasting Ocean Assimilation Model (FOAM) of the Met Office. Surface currents, temperatures and height together determine iceberg advection and melting rates. Iceberg drift is further governed by surface winds, which are updated every 3 h. The flux of icebergs from the Greenland ice sheet is determined from engineering control theory and specified as an upstream flux in the vicinity of Davis Strait for January or February. Simulated iceberg distributions are evaluated alongside observations reported and archived by the International Ice Patrol. The best agreement with observations is obtained when variability in both upstream iceberg flux and oceanographic/atmospheric conditions is taken into account. Including interactive icebergs in an ocean–atmosphere model with sufficient seasonal forecast skill, and provided with accurate winter iceberg fluxes, it is concluded that seasonal forecasts of spring/summer iceberg conditions for the northwest Atlantic are now a realistic prospect